How many weeks of pregnancy is nt

Nt test is a must-do test during pregnancy checkup. This test is also called trisomy 21 screening. It is a test that needs to be done in the early stages of pregnancy. It is mainly used to screen whether the fetus has chromosomal abnormalities. However, when doing this test, you must master the time of the test, otherwise the nuchal translucency that needs to be tested will disappear. So how many weeks of pregnancy is it appropriate to do nt test?

I believe that some people do not know what NT is. NT is an examination item in prenatal examination. It is used to determine whether the fetus is healthy through the transparency of the fetal neck. It is also the first "deformity examination" in prenatal examination. But how many weeks of pregnancy should you do the NT test?

NT is a B-ultrasound test used to screen for trisomy 21 at around 11-13 weeks of pregnancy. The use of ultrasound to measure the thickness of the nuchal translucency has very important clinical significance. As the thickness increases, the possibility of fetal abnormalities also increases. NT screening refers to the thickness of the nuchal translucency and the serum test of pregnant women. The nuchal translucency refers to the space where water accumulates under the skin behind the fetus' neck. During an ultrasound scan, the doctor will measure the thickness of the space between the skin and tissue in detail. The nuchal translucency will be significantly thickened in fetuses with chromosomal abnormalities, especially in babies with Down syndrome. Down syndrome is usually more likely to occur in older mothers. Medical literature has confirmed that the thicker the nuchal translucency of the fetus, the higher the chance of chromosomal abnormalities.

The fetus usually undergoes NT examination at around 12 weeks. Because the changes in the nuchal translucency are closely related to the gestational age, the measurement of the nuchal translucency is limited to 10-14 weeks of pregnancy. During a normal 10-14 week pregnancy, the thickness of the nuchal translucency increases slightly with the gestational age. A rough and simple estimation method is to judge any value less than 2.5 mm as normal, and any value greater than or equal to 2.5 mm as thickened nuchal translucency. The nuchal translucency disappears after 14 weeks of pregnancy. The thickness of the fetal neck skin can be measured between 14 and 21 weeks of pregnancy, which is also an effective indicator. When the thickness of the neck skin is greater than or equal to 6mm, the possibility of fetal chromosomal abnormalities should be considered. The positive detection rate is 39-56%.

Related research has found that if the child's nuchal translucency thickens during the 11-14 weeks of pregnancy, it means that the fetus may have Down syndrome or poor heart development. In addition, thickening of the nuchal translucency is also related to fetal chromosome karyotype, fetal congenital heart disease and other structural malformations. The thicker the nuchal translucency, the greater the probability of fetal abnormalities. Therefore, the purpose of nuchal translucency examination is to diagnose chromosomal diseases and detect fetal abnormalities caused by various reasons at an early stage of pregnancy.

Therefore, for the health of the fetus, NT examination is very important. Expectant mothers must pay attention to this and do regular prenatal checkups!